Folding pliers

ABSTRACT

Folding pliers for bending sheet metal includes a first clamping area and a second clamping area. Clamping areas are connected for rotation about a first axis. A first handle piece, which is connected to the first clamping area, and a second handle piece is pivotably connected to the first handle piece. The second handle piece is connected to the second clamping area and is rotatable about a second rotation axis, so when the first handle piece is pivoted relative to the second handle piece from a transport position, the first clamping area is moved relative to the second clamping area to clamp a piece of sheet metal between the clamping areas. After this, another pivot movement of the first handle piece relative to the second handle piece causes rotational movement of the first clamping area and second clamping area about the second rotation axis to bend the clamped sheet metal.

The invention relates to folding pliers for bending sheet metal,comprising a first clamping area and a second clamping area, wherein theclamping areas are connected such that they can be rotated about a firstrotation axis, and also a first handle piece and a second handle piececonnected to the first handle piece in a pivotable manner, wherein thefirst handle piece is connected to the first clamping area.

From the prior art, various tools for folding sheet metal or bendingsheet metal have become known. However, tools from the prior art areunwieldy and heavy, for which reason said tools are, for example, notsuitable for folding or bending sheet metal on facades in a simplemanner.

This is addressed by the invention. The object of the invention is tospecify a tool of the type named at the outset which is light and easyto handle and can be used portably.

According to the invention, this object is attained with folding pliersof the type named at the outset in which the second handle piece isconnected to the second clamping area such that the second handle piececan be rotated about a second rotation axis, so that when the firsthandle piece is pivoted relative to the second handle piece from atransport position, the first clamping area is moved relative to thesecond clamping area such that a piece of sheet metal positioned betweenthe clamping areas can be clamped by the clamping areas, after which afurther pivot movement of the first handle piece relative to the secondhandle piece causes a rotational movement of the first clamping areatogether with the second clamping area about the second rotation axisrelative to the second handle piece, in order to bend the clamped sheetmetal.

Within the scope of the invention, it was found that a compact andlightweight device for bending sheet metal in a simple manner can beobtained if folding pliers are embodied accordingly and, in a movementof the handle pieces relative to one another, a piece of sheet metal isfirst clamped between the clamping areas and, in a further movement ofthe handle pieces relative to one another, the sheet metal issubsequently bent about the second rotation axis due to a movement ofthe clamping areas together with the sheet metal relative to the secondhandle piece. Folding pliers of this type can be embodied to belightweight and compact so that they can also be used portably forfacade work, for example. Normally, the sheet metal is clamped as resultof a movement of the clamping areas relative to one another about thefirst rotation axis and the sheet metal bent as a result of a movementof the clamping areas together with the clamped section of the sheetmetal about the second rotation axis with a continuous motion of thehandle pieces, in order to ensure convenient ease-of-operation.

To release the finished folded piece of sheet metal from the foldingpliers again, the first handle piece is simply moved in the oppositedirection of the movement for the clamping and folding of the sheetmetal, so that folded sheet metal can be released from the foldingpliers.

It has proven beneficial that the first rotation axis and the secondrotation axis are approximately parallel. A distance between therotation axes is typically less than 20 cm, in particular less than 10cm, and corresponds to a length of the desired fold or a length of thesection of sheet metal to be bent. The clamping areas typically extendfrom the first rotation axis to the second rotation axis so that a pieceof sheet metal is fully clampable preferably in a region between thefirst rotation axis and the second rotation axis, in order to evenlyload the sheet metal and thus obtain a clean edge.

It is beneficial if the sheet metal can essentially be clamped by theclamping areas over the entire area between the first rotation axis andthe second rotation axis. Thus, a clamping is continuously possible in aregion between the rotation axes. As a result, a clean bending of theclamped sheet metal, or the sheet metal fixed in place between theclamping areas by a force-fit, is achieved with smooth bent edges.

A constructionally simple, and at the same time robust, design isachieved if a rotatable connection between the clamping areas and/orbetween the second clamping area and the second handle piece is formedby a hinge, in particular a piano hinge. A uniform force transmissionover a length of the fold is thus also ensured.

It has proven effective that the first handle piece is connected to thefirst clamping area via a plate-shaped intermediate element, wherein thefirst handle piece is preferably connected to the plate-shapedintermediate element via at least two connection positions which arearranged in particular at an end. This ensures a uniform application offorce over a length of the fold, so that a particularly smooth andhigh-quality bent edge can be obtained.

Analogously, it has proven advantageous if the second handle piece isconnected to the second clamping area via a plate-shaped intermediateelement, wherein the second handle piece is preferably connected to theplate-shaped intermediate element via at least two connection positionswhich are arranged in particular at an end.

To enable a particularly compact transport, it is advantageous if thefirst clamping area is connected to the first handle piece in a rigidmanner, preferably at an angle of less than 100°, in particular lessthan 50°, preferably 15° to 35°. The handle pieces can then be arrangedsuch that they bear against one another in a transport position, fromwhich transport position a clamping of a piece of sheet metal and afolding are directly possible. Typically, the first clamping area andthe first handle piece are connected in the region of the first rotationaxis.

It is beneficial if the first clamping area is connected to the firsthandle piece in a rigid manner, wherein in a transport position, inwhich the handle pieces bear against one another, the clamping areas arearranged at an opening angle of 10° to 90°, in particular 15° to 35°,preferably approximately 20°, to one another and are open in order toaccommodate a piece of sheet metal. On the one hand, a space-savingtransport is thus possible. On the other hand, the folding pliers canthen be used for the folding or of sheet metal directly from thetransport position.

To ensure that a rotation about the second rotation axis does not occuruntil the first clamping area is connected to the second clamping areain a form-fit, possibly via a piece of sheet metal clamped between theclamping areas, it is preferably provided that, in the transportposition, a torque that is necessary to move the second handle pieceabout the second rotation axis relative to the second clamping area isgreater than a torque that is necessary to move the first handle pieceabout the first rotation axis relative to the second clamping area, sothat a movement of the first handle piece out of the transport positionfirst initiates a movement of the first handle piece relative to thesecond clamping area. Constructionally, this can be implemented in themost varying ways, in particular through joints that move with differingdegrees of ease, which joints form the rotation axes.

A robust design of rotation axes which move with differing degrees ofease can easily be achieved if at least one spring is provided on ajoint that forms the second rotation axis, in particular on a pianohinge forming the second rotation axis, with which spring a frictionforce acting between parts of the joint that can be moved relative toone another can be applied to the joint, in order to define a torquenecessary for initiating a movement of the joint, wherein a spring forcecan be adjusted in particular by a set screw. For example, spring-loadedpressure pieces acting on parts of the second rotation axis that aremoved relative to one another can be provided so that a movement of thehinge or a movement of the second clamping area about the secondrotation axis relative to the second handle piece is only possible whenovercoming a frictional torque produced by the spring or a frictionforce acting on the parts of the second rotation axis that can be movedrelative to one another. Of course, it is also possible that more thanone spring is provided, in order to apply a uniform friction force overa length of the hinge. The spring thus acts, for example, directly on afirst part of the joint forming the second rotation axis, which firstpart can be moved relative to a second part of said joint, and pressesthe first part against the second part with the spring force, so that inorder to move the first part relative to the second part it is necessaryto overcome a friction force that is defined by the spring force and afriction coefficient.

Additional features, advantages and effects of the invention follow fromthe exemplary embodiment illustrated below. The drawings which arethereby referenced show the following:

FIGS. 1 through 3 Folding pliers according to the invention in differentoperating states;

FIG. 4 Folding pliers according to the invention together with a pieceof sheet metal;

FIG. 5 A detailed view of folding pliers according to the invention fromFIG. 4;

FIG. 6 Folding pliers according to the invention together with a pieceof sheet metal;

FIG. 7 A further set of folding pliers according to the inventiontogether with a piece of sheet metal.

FIGS. 1 through 3 show folding pliers 1 according to the invention indifferent operating states. As can be seen, the folding pliers 1comprise a first handle piece 6 and a second handle piece 7, wherein thefirst handle piece 6 is connected to a first clamping area 2 in a rigidmanner. The first handle piece 6 and the first clamping area 2 are, asis illustrated, connected to a second clamping area 3 such that they canbe rotated about a first rotation axis 4, so that a section of a pieceof sheet metal 8 or the like can be clamped between the clamping areas2, 3.

The second clamping area 3 is rotatably connected to a second handlepiece 7 via a second rotation axis 5 that is parallel to the firstrotation axis 4, so that a piece of sheet metal 8 clamped between theclamping areas 2, 3 can be bent or folded as the result of a rotationalmovement of the clamping areas 2, 3, which are connected via the clampedpiece of sheet metal, about the second rotation axis 5.

Both the movement of the first clamping area 2 about the first rotationaxis 4 relative to the second clamping area 3 and also the bendingmovement of the two clamping areas 2, 3 about the second rotation axis 5can be initiated by a movement of the first handle piece 6 relative tothe second handle piece 7, so that a clamping and bending of sheet metal8 can take place with a continuous motion of the first handle piece 6relative to the second handle piece 7.

In FIG. 1, the folding pliers 1 are illustrated in a transport positionin which the folding pliers 1 have a minimal space requirement and thehandle pieces 6, 7 essentially bear against one another. A clamping andfolding of a piece of sheet metal 8 is directly possible from thistransport position. To do so, a piece of sheet metal 8 that is to befolded is positioned between the clamping areas 2, 3 of the foldingpliers 1, which areas are opened at an opening angle β of approximately10° to 35° in this transport position.

To clamp a piece of sheet metal 8 positioned between the clamping areas2, 3, or to fix said sheet metal 8 in place between the clamping areas2, 3 in a force-fit, a first handle piece 6 of the folding pliers 1 ismoved relative to a second handle piece 7 of the folding pliers 1clockwise from the position illustrated in FIG. 1 in a direction ofmovement 13. Since the first clamping area 2 is connected to the firsthandle piece 6 in a rigid manner, a rotational movement of the firsthandle piece 6 also causes a rotational movement of the first clampingarea 2 relative to the second clamping area 3, whereby a piece of sheetmetal 8 positioned between the clamping areas 2, 3 is clamped by theclamping areas 2, 3 when the first handle piece 6 is moved clockwiserelative to the second handle piece 7. A position of this type, in whichthe clamping areas 2, 3 are closed, that is, in which an opening angle βbetween the clamping areas 2, 3 is 0°, is illustrated in FIG. 2.

From the position illustrated in FIG. 2, in a further movement of thefirst handle piece 6 relative to the second handle piece 7 in thedirection of movement 13, no further movement of the first handle piece6 about the first rotation axis 4 relative to the second clamping area 3is henceforth possible, especially since the clamping areas 2, 3 arealready closed. A further movement of the first handle piece 6 relativeto the second handle piece 7 clockwise in the direction of movement 13from the clamping position illustrated in FIG. 2 therefore causes arotational movement of the clamping areas 2, 3, together with the sheetmetal 8, and of the first handle piece 6 clockwise about the secondrotation axis 5. In this movement, the piece of sheet metal 8 clampedbetween the clamping areas 2, 3 is bent. A bending position in which theclamping areas 2, 3 are closed, and are accordingly pivoted relative tothe second handle piece 7 is illustrated in FIG. 3. Here, it can also beseen that the first clamping area 2 is connected to an intermediateelement 10 at an angle α of approximately 50°, via which intermediateelement 10 the first clamping area 2 is connected to the first handlepiece 6 in a rigid manner.

To release the finished folded or bent piece of sheet metal 8 from thefolding pliers 1, the first handle piece 6 is simply moved in theopposite direction of the direction of movement 13 for the clamping andbending, that is, counterclockwise in this case, so that the clampingareas 2, 3 are opened and the sheet metal 8 is released.

FIGS. 4 through 6 show folding pliers 1 according to the invention in anoperating position as illustrated in FIG. 3, but together with a pieceof sheet metal 8 clamped between the clamping areas 2, 3. As can beseen, the sheet metal 8 is bent in the region of the second rotationaxis 5. This has occurred as a result of the movement sequence describedabove.

As illustrated, the handle pieces 6, 7 are connected to the clampingareas 2, 3 via plate-shaped intermediate elements 10, wherein the handlepieces 6, 7 are arranged in end regions of the plate-shaped intermediateelements 10, or are connected to the handle pieces 6, 7 at connectionpositions 11 arranged at an end, in order to ensure a uniform forcetransmission and application to the sheet metal 8.

Particularly in FIG. 6, it can be seen that the first rotation axis 4and the second rotation axis 5 are in this case constructionally formedby piano hinges 9, in order to transmit forces in a particularly uniformmanner.

Of course, a length of the plate-like intermediate elements 10 and ofthe rotation axes 4, 5 is selected in accordance with a piece of sheetmetal 8 that is to be folded or bent, and is individually adaptable ifnecessary. Analogously, a length of the handle pieces 6, 7 and adistance of the same from the rotation axes 4, 5 can be adapted to aspecific application case, so that a simple actuation of the foldingpliers 1 and a simple folding of sheet metal 8 are respectively possiblethrough corresponding lever lengths.

FIG. 7 shows a further exemplary embodiment of folding pliers 1according to the invention together with a piece of sheet metal 8,wherein the folding pliers 1 are embodied essentially analogously to thefolding pliers 1 illustrated in FIG. 6, but additionally comprisesprings in the region of the second rotation axis 5, which springs areattached by set screws 12. A friction force acting between parts of thepiano hinge 9 forming the second rotation axis 5, which parts can bemoved relative to one another, is thereby produced via the springs, sothat a frictional torque produced by these springs must be overcomebefore the second clamping area 3 can be moved relative to the secondhandle piece 7 about the second rotation axis 5. No such springs areprovided at the first rotation axis 4, for which reason a torque forrotating the second clamping area 3 relative to the second handle piece7 about the second rotation axis 5 is greater than a torque for rotatingthe first handle piece 6 about the first rotation axis 4 relative to thesecond clamping area 3. It is thus ensured that, in a pivot movement ofthe first handle piece 6 in the direction of movement 13 from thetransport position illustrated in FIG. 1, a rotational movement of thefirst handle piece 6 together with the first clamping area 2 about thefirst rotation axis 4 relative to the second clamping area 3 initiallyoccurs, and a rotational movement of the first clamping area 2 togetherwith the second clamping area 3 about the second rotation axis 5 doesnot occur until the first clamping area 2 is connected to the secondclamping area 3 in a form-fit, or bears thereagainst, possibly via apiece of sheet metal 8 or the like clamped between the clamping areas 2,3. A sequence of the movements during the opening of the folding pliers1 is thereby analogously defined. This ensures a simple handling of thetool. An amount of the frictional torque that is to be overcome canthereby be adjusted via the set screws 12, via which a pretension of thesprings can be set.

Folding pliers 1 according to the invention are space-saving,lightweight and easy to handle, for which reason they can also easily beused in a portable manner, for example, to bend pieces of sheet metal 8on facades and the like. In addition, the folding pliers 1 according tothe invention are embodied to be robust, so that they are also suitablefor rough use conditions, in particular at construction sites.

1. Portably usable folding pliers for bending sheet metal, comprising afirst clamping area and a second clamping area, wherein the clampingareas are connected such that they can be rotated about a first rotationaxis, and also a first handle piece and a second handle piece connectedto the first handle piece in a pivotable manner, wherein the firsthandle piece is connected to the first clamping area, wherein the secondhandle piece is connected to the second clamping area such that thesecond handle piece can be rotated about a second rotation axis, so thatwhen the first handle piece is pivoted relative to the second handlepiece in a direction of movement 13 from a transport position, the firstclamping area is moved relative to the second clamping area such that apiece of sheet metal positioned between the clamping areas can beclamped by the clamping areas, after which a further pivot movement ofthe first handle piece relative to the second handle piece in thedirection of movement 13 causes a rotational movement of the firstclamping area together with the second clamping area about the secondrotation axis relative to the second handle piece, in order to bend theclamped sheet metal.
 2. The folding pliers according to claim 1, whereinthe first rotation axis and the second rotation axis are approximatelyparallel.
 3. The folding pliers according to claim 1, wherein the sheetmetal can essentially be clamped by the clamping areas over the entirearea between the first rotation axis and the second rotation axis. 4.The folding pliers according to claim 1, wherein a rotatable connectionbetween the clamping areas and/or between the second clamping area andthe second handle piece is formed by a hinge, in particular a pianohinge.
 5. The folding pliers according to claim 1, wherein the firsthandle piece is connected to the first clamping area via a plate-shapedintermediate element, wherein the first handle piece is preferablyconnected to the plate-shaped intermediate element via at least twoconnection positions which are arranged in particular at an end.
 6. Thefolding pliers according to claim 1, wherein the second handle piece isconnected to the second clamping area via a plate-shaped intermediateelement, wherein the second handle piece is preferably connected to theplate-shaped intermediate element via at least two connection positionswhich are arranged in particular at an end.
 7. The folding pliersaccording to claim 1, wherein the first clamping area is connected tothe first handle piece in a rigid manner, wherein in a transportposition, in which the handle pieces bear against one another, theclamping areas are arranged at an opening angle of 10° to 90°, inparticular 15° to 35°, preferably approximately 20°, to one another andare open in order to accommodate a piece of sheet metal.
 8. The foldingpliers according to claim 1, wherein, in the transport position, atorque that is necessary to move the second handle piece about thesecond rotation axis relative to the second clamping area is greaterthan a torque that is necessary to move the first handle piece about thefirst rotation axis relative to the second clamping area, so that amovement of the first handle piece out of the transport position firstinitiates a movement of the first handle piece relative to the secondclamping area.
 9. The folding pliers according to claim 8, wherein atleast one spring is provided on a joint which forms the second rotationaxis, in particular on a piano hinge forming the second rotation axis,with which spring a friction force acting between parts of the jointthat can be moved relative to one another can be applied to the joint,in order to define a torque necessary for initiating a movement of thejoint, wherein a spring force can be adjusted in particular by a setscrew.